Feeding rate and frequency on juvenile pompano growth

O objetivo deste trabalho foi avaliar a taxa e a frequência alimentar ideal para juvenis de pampo (Trachinotus marginatus). Foram conduzidos dois experimentos, em delineamento inteiramente casualizado, com três repetições cada um. No experimento I, 25 peixes (4,8±0,6 g e 6,48±0,01 cm) foram estocados em 15 tanques (50 L) durante 21 dias e alimentados com 4, 8, 12, 16 e 20% da biomassa total por dia. No experimento II, 20 peixes (4,1±0,1 g e 6,6±0,1 cm) foram estocados em 15 tanques (40 L) durante 28 dias e alimentados 2, 6, 8 e 10 vezes por dia. As taxas e as frequências alimentares testadas não influenciaram a sobrevivência. O peso e o comprimento finais no experimento I foram significativamente menores nos peixes alimentados com 4% da biomassa total por dia, enquanto, no experimento II, somente o peso foi significativamente menor nos peixes alimentados 2 e 6 vezes por dia. Ao final dos dois experimentos, a conversão alimentar aparente apresentou diferença significativa, com pior valor observado nos peixes alimentados com 20% da biomassa total por dia, no experimento I, e 2 vezes por dia no experimento II. Juvenis de pampo apresentam melhor desempenho de crescimento quando alimentados com 8% da biomassa total por dia e oito vezes por dia.The objective of this work was to evaluate the ideal feeding rate and frequency for juvenile pompano (Trachinotus marginatus). Two experiments were carried out in a completely randomized design, with three replicates each. In experiment I, 25 fish (4.8±0.6 g and 6.48±0.01 cm) were stocked in 15 tanks (50 L) during 21 days and fed 4, 8, 12, 16, and 20% body weight per day. In experiment II, 20 fish (4.1±0.1 g and 6.6±0.1 cm) were stocked in 15 tanks (40 L) during 28 days and fed 2, 6, 8, and 10 times a day. The tested feeding rates and frequencies did not influence survival. Final weight and length in experiment I were significantly lower in fish fed 4% body weight per day, whereas in experiment II only weight was significantly lower in fish fed 2 and 6 times a day. At the end of both experiments, apparent feed conversion showed significant difference, with the worst value observed for fish fed 20% body weight per day in experiment I and 2 times a day in experiment II. Juvenile pompano show better growth performance when fed 8% body weight per day and 8 times a day

Reprodução, desenvolvimento embrionário e larvicultura do “neon goby” Elacatinus Figaro em laboratório

Dissertação(mestrado)-Universidade Federal do Rio Grande, Programa de Pós-Graduação em Aqüicultura, Instituto de Oceanografia, 2008.O “neon goby” Elacatinus figaro é endêmico da costa brasileira e foi uma das espécies mais importantes no comércio de peixes ornamentais marinhos do país. Atualmente, encontra-se na lista de espécies ameaçadas de extinção e resguardadas do extrativismo. Este trabalho teve como intuito descrever a reprodução, o desenvolvimento embrionário e a larvicultura do “neon goby” em laboratório. As primeiras desovas naturais foram observadas a partir do 24° dia após a formação dos casais, sendo o intervalo entre as desovas de 8 a 10 dias a 26°C. A fecundidade variou de 430 a 1.020 ovos por desova com média de 648 ± 183 ovos (média ± desvio padrão1, com taxa de eclosão média de 69 ± 16% Os ovos são elípticos, medem 1,81 ± 0,1 mm de comprimento e 0,61 ± 0,03 mm de diâmetro, eles apresentam filamentos adesivos na parte basal e contêm cinco protuberâncias na parte distal. O tempo para eclosão das larvas é de 7 a 8 dias. As larvas recém eclodidas medem 3,15 ± 0,07 mm, apresentam fototaxia positiva, olhos pigmentados, boca aberta e vesícula gasosa inflada. As larvas foram alimentadas com rotíferos Brachionus plicatilis em sistema de água verde com a microalga Nannochloropsis oculata do 1° ao 20° dia após a eclosão. Náuplios de Artemia foram oferecidos a partir do 15 ° dia em conjunto com rotíferos e, exclusivamente, a partir do 20° dia. O assentamento ocorreu a partir do 28° dia, quando as larvas do “neon goby” atingiram comprimento de 8,50 ± 0,18 mm com sobrevivência entre 2 e 20%.The “neon goby” Elacatinus figaro is endemic of the Brazilian coast and was one of the most important species in the marine ornamental fish trade in the country. Today it is on the list of endangered species and it can no longer be collected in the wild. This work was carried out in order to describe natural breeding, embryonic development and larviculture of neon goby in laboratory. The first natural spawning was observed 24 days after the pairs were formed 8 to 10 days at 26°C. Mean fecundity was 648 ± 183 (± SD) eggs per clutch and ranged from 430 to 1020 eggs, the hatching rate was 69 ± 16%. Eggs are elliptical in shape, they present adhesive filaments at the proximal end and five protuberances at the distal end. Egg length averaged 1.81 ± 0.1 mm and maximum width was 0.61 ± 0.03 mm. The embryonic developmental period lasts between 7 and 8 days. The newly hatched larvae measure 3.15 ± 0.07 mm, showing positive phototaxis, pigmented eyes, mouth opened and insufflated gas bladder. Larvae were fed with rotifers Brachionus plicatilis in green water system along with the microalgae Nannochloropsis oculata from day 1 to day 20 day after hatching. Artemia nauplii were added to the diet on day 15, and 5 days later rotifers were no longer offered. Larvae began to settle to the bottom on day 28, when length of neon goby was 8.50 ± 0.18 mm, the final survival rate ranged between 2 and 20%

Use of commercial live feeds enrichment during first feeding period of the barber goby Elacatinus figaro

The first feeding period is the most critical phase for the production of marine fish larvae. The utilization of n-3 HUFA enrichment on live feed has improved the results for several species during the larviculture. To evaluate the effect of n-3 HUFA enrichment on survival and growth of the barber goby Elacatinus figaro Sazima, Moura & Rosa, 1997, newly hatched larvae were divided in two experimental groups(200 larvae per group, with two replicates each). One group was fed on non-enriched rotifers Brachionus plicatilis and the other group was fed with n-3 HUFA enriched rotifers. After 14 days of experiment, survival of larvae fed n-3 HUFA enriched rotifers was three times higher (35.7 ± 3.1%) than those fed non-enriched rotifers (11.1 ± 5.2 %), however this difference was not significant. Growth was faster for larvae fed n-3 HUFA enriched rotifers after the first week of life, but at the end of 14 days, it was no longer significantly different between the two groups(6.09 ± 0.62 and 5.69 ± 0.66 mm). The results of this experiment suggest that barber goby should be fed n-3 HUFA enriched rotifer in order to maximize juvenile production

Production of juvenile barber goby Elacatinus figaro in captivity: developing technology to reduce fishing pressure on an endangered species

The barber goby Elacatinus figaro, native to the Brazilian Atlantic coast, is endangered due to over-exploitation by the ornamental industry. It is expected that once the technology for juvenile production is mastered, one could reduce fishing pressure by commercializing fish raised in captivity and stocking enhancement programmes can be established. This work was carried out in order to describe natural breeding, embryonic development and larviculture of barber goby in the laboratory. The first spawning was observed 24 days after the pairs were formed, thereafter barber goby spawned every 8 to 10 days at 268C. Fecundity ranged from 430 to 1020 eggs per clutch with average hatching rate of 69 +16%. Fertilized eggs are elliptical in shape and present adhesive filaments at the proximal end and five protuberances at the distal end. Egg length averaged 1.81 +0.1 mm and mean width was 0.61 +0.03 mm. The embryonic developmental period lasted 7 days and newly hatched larvae measured 3.15 +0.07 mm, showing positive phototaxis. Larvae were fed with rotifers Brachionus plicatilis in green water culture along with the microalgae Nannochloropsis oculata from 1 to 20 days after hatching (DAH). Artemia nauplii were added to the diet 15 DAH, and 5 days later rotifers were no longer offered. The results of the present study demonstrate the viability to produce naturally spawned eggs of the barber goby E. figaro in captivity. Larvae settle to the bottom 28 to 35 DAH, when total length was equal to 8.5 mm in average

CULTIVE OF THE MARINE MICROALGAE Chaetoceros calcitrans (BACILLARIOPHYCEAE) USING DIFFERENTS BRANDS OF ARTIFICIAL MARINE SALT WATER

The use of microalgae as live food to a wide variety of organisms is one of the most important aspects in aquaculture. Several commercial formulations have been available in the marine aquarium market in order to prepare artificial sea water (ASW). The present study accounted microalgae Chaetoceros calcitrans performance cultured using different ASW in comparison to natural seawater(NSW). it was carried out using red Sea, Coralife and oceanic, three different ASW brands and NSW as control. nonaerated cultures were grew in 400 mL with Conwy culture medium with five replicates each under defined conditions. All cultures began with an algal inoculum of 208.000 cells/mL. a 5-mL aliquot was removed daily from each culture for cells counts. data obtained using polynomial regression test demonstrated that all ASW brands reached higher algal density rates than the one with NSW, though the three ASW brands were significantly heterogeneous. C. calcitrans raised with oceanic and red Sea brands showed similar growth rates and both were higher than Coralife brand. the results suggest that all three ASW brands studied can be used in the culture of this microalgae specie

Feeding rate and frequency on growth of juvenile pompano

The objective of this work was to evaluate the ideal feeding rate and frequency for juvenile pompano (Trachinotus marginatus). Two experiments were carried out in a completely randomized design, with three replicates each. In experiment I, 25 fish (4.8±0.6 g and 6.48±0.01 cm) were stocked in 15 tanks (50 L) during 21 days and fed 4, 8, 12, 16, and 20% body weight per day. In experiment II, 20 fish (4.1±0.1 g and 6.6±0.1 cm) were stocked in 15 tanks (40 L) during 28 days and fed 2, 6, 8, and 10 times a day. The tested feeding rates and frequencies did not influence survival. Final weight and length in experiment I were significantly lower in fish fed 4% body weight per day, whereas in experiment II only weight was significantly lower in fish fed 2 and 6 times a day. At the end of both experiments, apparent feed conversion showed significant difference, with the worst value observed for fish fed 20% body weight per day in experiment I and 2 times a day in experiment II. Juvenile pompano show better growth performance when fed 8% body weight per day and 8 times a day.O objetivo deste trabalho foi avaliar a taxa e a frequência alimentar ideal para juvenis de pampo (Trachinotus marginatus). Foram conduzidos dois experimentos, em delineamento inteiramente casualizado, com três repetições cada um. No experimento I, 25 peixes (4,8±0,6 g e 6,48±0,01 cm) foram estocados em 15 tanques (50 L) durante 21 dias e alimentados com 4, 8, 12, 16 e 20% da biomassa total por dia. No experimento II, 20 peixes (4,1±0,1 g e 6,6±0,1 cm) foram estocados em 15 tanques (40 L) durante 28 dias e alimentados 2, 6, 8 e 10 vezes por dia. As taxas e as frequências alimentares testadas não influenciaram a sobrevivência. O peso e o comprimento finais no experimento I foram significativamente menores nos peixes alimentados com 4% da biomassa total por dia, enquanto, no experimento II, somente o peso foi significativamente menor nos peixes alimentados 2 e 6 vezes por dia. Ao final dos dois experimentos, a conversão alimentar aparente apresentou diferença significativa, com pior valor observado nos peixes alimentados com 20% da biomassa total por dia, no experimento I, e 2 vezes por dia no experimento II. Juvenis de pampo apresentam melhor desempenho de crescimento quando alimentados com 8% da biomassa total por dia e oito vezes por dia